PTU-187 Sample size calculation in confirmatory trials in irritable bowel syndrome with constipation: experience with linaclotide (constella®): Abstract PTU-187 Table 1

Background: Spasmolytic agents are an attractive first line treatment option for irritable bowel syndrome (IBS). Pinaverium bromide (pinaverium) has antispasmodic effects on gastrointestinal smooth muscle and can relieve major IBS symptoms, but an up-to-date meta-analysis comparing the efficacy of pinaverium with placebo is lacking. The aim is to perform a systematic review and meta-analysis to assess the efficacy of pinaverium compared with placebo for IBS treatment. Methods: All placebo-controlled trials evaluating pinaverium for IBS treatment were included, up to October 2019. Treatment efficacy was evaluated by overall patient IBS symptoms. Individual symptoms were also evaluated. The effect of pinaverium versus placebo was expressed as standardized mean difference (SMD) and risk ratio (RR). Odds ratio (OR) and number needed to treat (NNT) were also calculated. Results: Eight studies were included for analysis. Pinaverium treatment had a beneficial effect on overall IBS symptom relief with a positive SMD of 0.64 [95% confidence interval (CI) 0.45–0.82, p < 0.0001] and a positive RR of 1.75 (1.26–2.43, p < 0.0008). No significant difference was found by publication year, gender, age, methodological quality score (MQS), or sample size. No publication bias was detected. OR was 3.43 (2.00–5.88, p < 0.0001), and NNT was 4. Pinaverium also demonstrated a beneficial treatment effect for abdominal pain, stool change, and bloating improvement or resolution. Conclusion: Pinaverium is superior to placebo for the treatment of IBS symptoms, irrespective of patient age or gender, study publication year, sample size, or MQS. The NNT in this meta-analysis is amongst the lowest for studies and meta-analyses of antispasmodics versus placebo in IBS.

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Acupuncture for Irritable Bowel Syndrome – An Exploratory Randomised Controlled Trial

Acupuncture in Medicine ◽

10.1136/aim.26.1.8 ◽

2008 ◽

Vol 26 (1) ◽

pp. 8-16 ◽

Cited By ~ 35

Author(s):

Julie A Reynolds ◽

J Martin Bland ◽

Hugh MacPherson

Keyword(s):

Irritable Bowel Syndrome ◽

Randomised Controlled Trial ◽

Sample Size ◽

Primary Outcome ◽

Controlled Trial ◽

Full Scale ◽

Clinically Significant ◽

Irritable Bowel ◽

Randomised Controlled ◽

Gp Care

Background The evidence on the effectiveness of acupuncture for irritable bowel syndrome (IBS) is inconclusive. However, many patients with IBS are self referring for acupuncture, therefore it is of interest to know whether acupuncture is effective or not. The aim of this study was to establish variability in the primary outcome measure to enable a sample size to be calculated for a full scale trial, and to explore feasibility and design criteria. Methods A pragmatic randomised controlled trial compared 10 sessions of acupuncture plus usual GP care with usual GP care alone. Thirty patients were recruited from four GP databases in Birmingham, UK, and randomised one-to-two to acupuncture or usual care alone. The primary outcome was the IBS Symptom Severity Score (SSS) at three months (maximum score 500). Analysis was by intention-to-treat, and multiple imputation was used for missing data. Results From the databases, 189 patients with IBS were identified, of whom 30 were eligible and consented to randomisation. At three months, a statistically and clinically significant difference between groups of 138 points (SD 90) in favour of acupuncture was observed on the IBS SSS (95% CI: 66 to 210; P=0.001) using multiple imputation. For a full scale trial, we estimate that a sample size of 108 patients per arm is required, based on a minimum clinically significant change of 50 points, drawn from a primary care population of 140 000. Conclusions We established the feasibility of a full scale trial, successfully recruiting patients and calculating the sample size required. The results of our pilot analysis suggest that more definitive research into acupuncture for IBS is merited. A pragmatic trial design will not be able to distinguish between acupuncture specific effects and placebo effects; however, it is the design of choice to determine cost effectiveness.

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